How to Print Exception Messages in Python?

You can print exception messages in Python using the built-in try...except block and the sys.exc_info() function.

Using try...except Block

The try...except block allows you to handle exceptions gracefully. If an exception occurs within the try block, the code within the corresponding except block will be executed.

try:
    # Code that might raise an exception
    result = 10 / 0
except ZeroDivisionError as e:
    print(f"Error: {e}")

In this example, dividing by zero raises a ZeroDivisionError. The except block catches this exception and prints the error message using an f-string.

Using sys.exc_info() Function

The sys.exc_info() function returns information about the current exception, including the exception type, value, and traceback.

import sys

try:
    # Code that might raise an exception
    result = 10 / 0
except:
    exc_type, exc_value, exc_traceback = sys.exc_info()
    print(f"Error type: {exc_type}")
    print(f"Error value: {exc_value}")
    print(f"Traceback: {exc_traceback}")

This code catches any exception and prints the exception type, value, and traceback.

Practical Insights

• You can use the else block within the try...except block to execute code only if no exception occurs.
• The finally block executes regardless of whether an exception occurred or not.
• You can specify multiple except blocks to handle different types of exceptions.

Examples

Here are some examples of how to print exception messages in Python:

Example 1: Printing the exception message directly

try:
    # Code that might raise an exception
    result = 10 / 0
except ZeroDivisionError as e:
    print(f"Error: {e}")

Example 2: Using the sys.exc_info() function to get detailed information about the exception

import sys

try:
    # Code that might raise an exception
    result = 10 / 0
except:
    exc_type, exc_value, exc_traceback = sys.exc_info()
    print(f"Error type: {exc_type}")
    print(f"Error value: {exc_value}")
    print(f"Traceback: {exc_traceback}")

Example 3: Handling multiple exception types

try:
    # Code that might raise an exception
    result = 10 / 0
except ZeroDivisionError as e:
    print(f"Error: Cannot divide by zero: {e}")
except TypeError as e:
    print(f"Error: Invalid data type: {e}")
except Exception as e:
    print(f"Error: An unexpected error occurred: {e}")

This code handles three different exception types: ZeroDivisionError, TypeError, and any other exception using the Exception class.